Chinese media speculated early on – before all unauthorized coverage was banned by the propaganda department – that the 7.23 Wenzhou bullet train collision was possibly caused by the signal system. A Wall Street Journal (WSJ) article on Monday seems to point into the same direction, and says that China used foreign technology in its bullet-train signal systems which local engineers couldn’t fully understand, according to a review of corporate documents and interviews with more than a dozen rail executives inside and outside China.
However, the authors add that the precise cause of the crash remained uncertain, and that the signaling assembly hadn’t necessarily played a role.
The WSJ authors mention both the Chinese supplier, and the inclusion of Hitachi technology which had been supplied as a “black box” by the Japanese company, for fear that it could be reverse-engineered in China otherwise. The Chinese manufacturer and the railway ministry reportedly didn’t respond to requests for comment.